Device for feeding stock in a screw machine



P. DUCA'NIS DEVICE FOR FEEDING STOCK IN A SCREW MACHINE Filed May 25, 1967 Dec. 10, 1968 2 Sheets-Sheet 1 INVENTOR. PAUL DUCANIS Dec. 10, 1968 P. DUCANIS DEVICE FOR FEEDING STOCK IN A SCREW MACHINE Filed May 23, 1967 2 Sheets-Sheet 2 1 \"VEVIOR. PAUL DUCANIS United States Patent 3,415,436 DEVICE FOR FEEDING STOCK IN A SCREW MACHINE Paul Ducanis, 1520 NE. 103rd St., Miami Shores, Fla. 33153 Filed May 23, 1967, Ser. No. 640,705 4 Claims. (Cl. 226-167) ABSTRACT OF THE DISCLOSURE A replacement for conventional feed fingers in an automatic screw machine comprising a sleeve containing a plurality of cantable rings for engaging and precisely sequentially feeding stock through said sleeve when the latter is reciprocated by the screw machine.

This invention relates in general to stock feeding devices for automatic screw machines and more particularly to a self locking device for replacing conventional feed fingers in a screw machine for producing improved dimensional tolerances of accuracy and longer life of the feed mechanism.

Reference is had to applicants Patent No. 3,322,317, Mechanism for sequentially Feeding Bars of Uniform Cross Section in a Machine.

The complexity and frequent faulty operation of conventional feed fingers in automatic or semi-automatic screw machines is overcome by the substitution of the present invention by the simple removal of the feed finger assembly and the substitution of a simplified self feeding and locking device, to be hereinafter described.

A principal object of the invention is the provision of a de-mountable tubular member having therein a plurality of loosely positioned rings for permitting stock of predetermined cross section to move freely in one direction and to be precisely engaged by said rings to prevent movement in the opposite direction.

A further object of the invention is the provision of a de-mountable cylinder in rings have predetermined internal diameters or configurations which may be quickly exchanged therein for feeding stock of different uniform cross sections.

These and other objects and advantages are described and shown in the following specification and drawings, in which:

FIG. 1 illustrates a portion of a typical screw machine for retaining the stock feed mechanism.

FIG. 2 is an enlarged side elevation of the stock feed device illustrated in FIG. 1.

FIG. 3 is a further enlarged fragmentary side elevation of the device shown in FIG. 2 with a portion thereof broken away.

FIG. 4 is an enlarged cross sectional side elevation taken through section line 4-4, FLIG. 2.

FIG. 5 is an enlarged cross sectional end elevation taken through section line 5-5, FIG. 2.

FIG. 6 is an enlarged cross sectional side elevation taken through section line 6-6, FIG. 2.

FIG. 7 is a perspective view of one of the feed elements shown in FIGS. 3 and 4.

FIG. 8 is an enlarged side elevation, the same as FIG. 2, with a portion broken away, illustrating the free unidirectional movement of stock therethrough.

FIG. 1 illustrates a conventional automatic mechanism 1 responsive to the movement of cams 2 and 3 for operating the feed device 4 to project typical round stock 5 of predetermined diameter a precise distance D for cutoff by machine mechanism, not shown.

3,415,436 Patented Dec. 10, 1968 ice Referring to FIG. 2, a sleeve or tubular member 6 threaded at its right hand end 7'is adapted to be threaded into the mechanism 1 with the aid of a spanner hole 8, (better shown in FIG. 4. A second tubular member 9 is coaxially retained to tubular member 6 by an external threaded coupling 10, better shown in FIG. 4, which has a secondary function to be hereinafter described.

Referring to FIG. 3, the inner end 11 of the coupling 10, also having a spanner hole 8, is made oblique with respect to the axis of the coupling and retains therein a plurality of lock rings 12 which are shown normal to the axis of the members 6, 9, and 11, which will permitf the free passage of a round stock 13, illustrated in dotted lines in left hand direction, against the action of a helical spring 14 retained in the outer end of tubular member 9 against a shoulder 15.

FIG. 4 illustrates the idle position of the device with the rings 12 canted against the oblique inner end of coupling 10 under the influence of spring 14.

Referring to FIGS. 2, 3, and 4, it is to be noted that an axial slot 16 is provided in member 9 for retaining an offset end 17 of spring 14, shown in FIG. 5, and also, each ring 12 has a projection 18 engaged in slot 16, as shown in FIGS. 6 and 7, to prevent the rotation therewith with reference to member 9.

Referring to FIG. 8 and under the assumption that cylinder members 6 and 9 are threaded into the receiver of a screw machine by the aid of suitable spanner engaging the holes 8 and that the inside diameter of each ring 12 is slightly greater than the outside diameter of the round stock to be fed, then if the stock is moved through the device in the direction shown by arrows at distance D, the movement will be freely made through the rings 12 by the action of the machine, not shown. Since the spring 14 at all times urges the rings 12 toward their canted position by virtue of the end of the oblique surface 11, any reverse movement of the stock will be prevented by a slight multiple canting of the rings 12, which will lock against the outer surface of the stock in a precise manner without damage thereto. The sequential reciprocation of the feed device 4, made by the machine, will result in corresponding sequential precise projection of the stock being machined.

It is to be noted that the foregoing description refers to the feeding of round stock of uniform diameter, however, one of the important features of the invention is the ability to feed stock of a Wide variety of geometric shape of uniform cross section, such as square or hexagonal, by providing rings 12 with apertures therethrough shaped accordingly and to permit the free movement therethrough for each particular geometric shape.

It is also to be noted that since most spindles in screw machines rotates counter-clockwise, the threads on coupling 10 and their mating threads in members 6 and 9 are correspondingly left hand.

It is further to be noted that the rings 12 are preferably made from wear resistant steel, heat treated to a high degree of hardness in order to prolong the life of the feeding mechanism.

It is to be understood that certain modifications in the above construction, utilizing the above features, are intended to come within the scope of the appended claims.

Having described my invention, I claim:

1. A cylindrical stock feed assembly for a screw machine adapted and constructed for sequential axial reciprocati-on and rotation by said machine along and about the axis thereof respectively comprising a cylinder assembly having a coaxial bore therethrough and means at one end portion thereof for securing same in said machine,

a plurality of like lock rings in stacked relation tiltably positioned in said bore for movement from an unlocked position normal the axis of said assembly to a tilted rest position with respect to said axis,

each of said rings having a like aperture therethrough and an inner periphery contour like the outer periphery contour of said stock for the free slidable movement of the latter through said rings when the latter are moved by said stock into their said unlocked position,

a circular shoulder in said cylinder adjacent the rear one of said rings with an inner planar surface thereof at a predetermined angle with respect to said axis as a stop for the said rear one of said rings for holding said stacked rings in said rest position,

a spring means in said bore biased between the outer end portion of said assembly and the front one of said rings for urging the latter into said rest position whereby said stock moved through said assembly from the rear thereof will move said rings into their said unlocked position against the restraining action of said spring means and whereby said stock will be prevented from reverse movement by the tilting and locking engagement of said rings on opposite sides of said stock when said rings are urged toward their said idle position.

2. In a stock feed assembly for a screw machine of the character described a means forming a hollow main cylinder for the free axial passage of said stock therethrough,

said cylinder having a coaxial bore of predetermined diameter therein terminating at the front end thereof in an inner depending shoulder of predetermined width,

a tubular stop member secured in the rear portion of said bore with the front edge surface thereof forming a planar shoulder in said bore of predetermined width at a predetermined angle with respectto the axis of said cylinder,

a plurality of like lock rings in stacked relation tiltably positioned in said bore between said first and said second mentioned shoulder,

said rings dimensioned for movement from an unlocked stacked position normal said axis to an idle stacked position tilted with the rearmost one thereof against said second mentioned shoulder,

each of said rings having a like aperture therethrough within an inner periphery contour like the outer periphery contour of said stock for the free slidable movement of the latter through said rings when the latter are moved by said stock into their said unlocked position,

a coil spring means in said bore biased between said first mentioned shoulder and the front one of said rings for urging the latter into said rest position whereby said stock moved through said cylinder from the rear thereof will move said rings into their said unlocked position against the restraining action of said spring means and whereby said stock Will be prevented from reverse movement by the tilting engagement of said rings on opposite sides of said stock when said rings are urged toward their said idle position.

3. The construction recited in claim 2 including a keyway in the wall of said cylinder parallel the axis thereof,

a projection extending from the outer periphery of each of said rings loosely engaged in said keyway,

one end of said spring means formed to engage said keyway whereby said rings and said spring means are prevented from rotating independent of the rotation of said cylinder when the latter is rotated about said axis.

4. The construction recited in claim 2 including a second cylinder having a bore therethrough for the free passage of said stock threaded to the rear end of said stop means in coaxial relation with said main cylinder for extending the effective length of said main cylinder,

said second cylinder threaded at the rear end thereof for engagement in said screw machine.

References Cited UNITED STATES PATENTS 3,112,056 11/1963 Wright et al 226-167 X 3,126,138 3/1964 Onulak 226167 X ALLEN N. KNOWLES, Primary Examiner. 

